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Item Long-Branch Attraction and the Phylogeny of True Water Bugs (Hemiptera: Nepomorpha) as Estimated from Mitochondrial Genomes(2014-05) Li, Teng; Hua, Jimeng M.; Wright, April M.; Cui, Ying; Xie, Qiang; Bu, Wenjun J.; Hillis, David M.; Wright, April M.; Hillis, David M.Most previous studies of morphological and molecular data have consistently supported the monophyly of the true water bugs (Hemiptera: Nepomorpha). An exception is a recent study by Hua et al. (BMC Evol Biol 9: 134, 2009) based on nine nepomorphan mitochondrial genomes. In the analysis of Hua et al. (BMC Evol Biol 9: 134, 2009), the water bugs in the group Pleoidea formed the sister group to a clade that consisted of Nepomorpha (the remaining true water bugs) + Leptopodomorpha (shore bugs) + Cimicomorpha (assassin bugs and relatives) + Pentatomomorpha (stink bugs and relatives), thereby suggesting that fully aquatic hemipterans evolved independently at least twice. Based on these results, Hua et al. (BMC Evol Biol 9: 134, 2009) elevated the Pleoidea to a new infraorder, the Plemorpha. Results: Our reanalysis suggests that the lack of support for the monophyly of the true water bugs (including Pleoidea) by Hua et al. (BMC Evol Biol 9: 134, 2009) likely resulted from inadequate taxon sampling. In particular, long-branch attraction (LBA) between the distant outgroup taxa and Pleoidea, as well as LBA among taxa in the ingroup, made Nepomorpha appear to be polyphyletic. We used three complementary strategies to test and alleviate the effects of LBA: (1) the removal of distant outgroups from the analysis; (2) the addition of closely related outgroups; and (3) the addition of a mitochondrial genome from a second family of Pleoidea. We also performed likelihood-ratio tests to examine the support for monophyly of Nepomorpha with different combinations of taxa included in the analysis. Furthermore, we found that specimens of Helotrephes sp. were misidentified as Paraplea frontalis (Fieber, 1844) by Hua et al. (BMC Evol Biol 9: 134, 2009). Conclusions: All analyses that included the addition of more taxa significantly and consistently supported the placement of Pleoidea within the Nepomorpha (i.e., supported the monophyly of the traditional true water bugs). Our analyses further support a close relationship between Notonectoidea and Pleoidea within Nepomorpha, and the superfamilies Nepoidea, Ochteroidea, Naucoroidea, and Pleoidea are resolved as monophyletic in all trees with strong support. Our results also confirmed that monophyly of Nepomorpha clearly is not refuted by the mitochondrial genome data.Item Monitoring DDT and PAHs in Barton Springs Sediment(City of Austin Watershed Protection Department, 2015) Richter, AaronBarton Springs is an environmentally-sensitive area which provides habitat for two endangered aquatic salamander species, supplies water to Barton Springs pool, and represents the primary discharge point for the Barton Springs segment of the Edwards Aquifer, a sole-source aquifer for the Austin area. DDT, DDD, DDE, and a list of polycyclic aromatic hydrocarbons (PAH) are toxic pollutants that have been monitored in the sediment at Barton Springs for at least 15 years. Trends of these pollutants over time were analyzed at Barton Springs and current concentrations of the pollutants present within the springs were compared to concentrations of the pollutants in sediment samples collected throughout Austin in 2013 and 2014. DDT, DDD, and DDE were not pollutants of concern for Barton Springs; however, PAH including benzo(a)anthracene, benzo(a)pyrene, benzo(e)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, chrysene, fluoranthene, indeno(1,2,3-cd)pyrene, phenanthrene, and pyrene have risen in concentration beginning in approximately 2006. While many samples at Barton Springs have not contained samples above probable effect concentration levels, investigation is warranted to determine why the PAH concentrations increased. The initial concern of this report was to address sediment pollution at Barton Springs but additional sites of concern were identified upon comparison of pollutant concentrations at Barton Springs to concentrations throughout Austin in 2013 and 2014. Most notably, sediment samples collected within the Harper’s Branch watershed indicate chronically toxic sediments and an investigation for a source should be conductedItem Reclaimed water irrigation water quality impact assessment, Phase 1 Summary of Results(City of Austin Watershed Protection Department, 2014) Clamann, Andrew; Hiers, Scott; Richter, Aaron; Scoggins, Mateo; Herrington, Chris